Data Extraction and Quality Assessment
Data from the eligible studies were subsequently extracted by two
authors (NA, AK) into a spreadsheet including information on the study
characterises (study design, setting, sample size, population,
exposure-ACEIs/ARBs, ACEIs, or ARBs) and outcome measures including
death, intensive care unit (ICU) admission, risk of COVID-19 infection,
severe COVID-19 infection, severe pneumonia, hospitalisation, hospital
discharge, use of ventilators, duration of hospital stay, septic shock,
acute kidney injury, cardiac injury, and hospital readmission. Since the
need for using ventilators typically necessitates ICU admission, we
combined studies that reported ICU admission and ventilator use as a
further composite outcome measure. Two authors (NA and LA) independently
conducted the assessment of risk of bias using the Newcastle-Ottawa
Scale (NOS) for nonrandomised studies (32), whereby studies were
classified into good, fair and poor quality (33). Some of the co-authors
have used this approach before (34).